Spark-plug.



G. L. FREEMAN.

SPARK PLUG.

APPLICATION FILED FEB.4. 1916.

1 ,%'Z, I Patented June 19, 1917.;

NITED s'ra'rns PATENT orrucn.

en'onen L. FREEMAN, or 'rrconn'nnoea, NEW YORK, assmn'on or ONE-HALF r0RICHARD r. HAYES, or 'rroonnnnoea, NEW Yonx.

sranx-rmuG.

' Specification of Letters Patent.

Application filed February 4, 1916. Serial No. 76,210.

for internal combustion engines and resides more especially in theproduction of a spark plug which can be readily affixed to any wellknown type of engine. I,

In practice it has been-found that after using a spark plug in theordinary type of engine where it 1s exposed to the products ofcombustion, anappreciable amount of carbon is soon deposited upon thepoints or between the'surfaces over which the spark jumps, and'theefliciency of the motor is materially reduced, sometimes to the extentof complete inoperativeness, until these plugs have been removed,the-points carefully cleaned, and the plug again positioned in; themotor.

Certain attempts to remedy this difliculty have been made and shields orprotecting guards have been arranged about the spark points so as todeflect the products of com bustion and prevent the collection of oiland carbon.

To some extent, devices of this character have addedto the efficiency ofthe motor for a period, but after continued usage the efliciency isagain reduced and the removing and cleaning of the plugs are required atfrequent intervals.

An object of the present invention is to overcome these existingdifliculties, and pro vide a spark plug in which the'accumulation of oiland, carbon is' prevented by means peculiarly a part of the sparkingterminals or. omts. 1

other object of the res'entinvention is the reduction of a s ar plugincluding, in

com ination, a mova le terminal; suppo and positioned upon the lower endof the plug and adapted to coact with an opposing stationary terminalfor preventing t e 'deositing of oil, carbon and other extraneous oreignmatters therebetween.

' With these and other objects in view, the

invention-further consists in the combination and arrangement of. partsadapted to ex-.

elude all barbon and oil, and add materially to the economic yalue ofthe plug for general use, as will more fully hereinafter appear.

In the drawings which show by way of illustration an embodiment of myll'lVGIltlOIl,

and in which similar reference characters designate like parts-'-Patented June 1a, 191?.

Figure 1 is a side elevation of my 2 proved spark plug. I

Fig. 2 is a vertlcal sectional view thereof. Fig. 3 is a detailperspective view of the tubular washer adapted to space the movableterminal and seal the space around the central stem or rod against theentrance of oil and carbon, and

milar view of the movable ter-' Fig. 4 is a si mina x Referring to thedrawings, my present in-' vention includes among other things an outershell 1 provided with the usual screw threads 2 for positioning the plugin thecylinder of a'motor (not shown). Thisshell has near the upper endthereof flattened or hexagonal surfaces 3, by means of which it can bereadily positioned and securely adjusted in the cylinder of a motor.

An insulating body portion 4 is arranged within. the shell 1 and isprovided with the usual tapering upper ortion 5, as shown.

The material from which this body portion 4 is made is preferablyporcelain, but it may be of other substances or compositions possessingthe. necessary characteristics to ermit of the proper'operation of the pu This body portion 4 is provided with shou ders 6, as shown in Fig. 1,against WhlOh a ably arranged near the top andbottom; respectively, ofthe outer shell 1, and is arsuitablepacking or sealing material 7 isinserted. This packing material 7 is preferthreaded into the upperportion of the shell,

as will be readily understood. By this construction it will be readilyseen that the body portion is completely sealed within the shell 1, andprotected; against the entrance of oil and car on. f p d The bodyportion 4 is provided with an opening 9 extendingthe length thereof, and

arranged to receive a rod or stem 10 threadedat the upper end as at 11and threaded movable terminal 14 in position. The usual at the lower endas at 12.. A head 13 is provided on the rod 10 and servestoholdthe capscrew and locking nut 16 are pro-.

, ed upon the rod or stem 10, and is provided I rod or'stem-10. In theoperation of the dewith a beveled upper surface 18. By this constructionit will be readily seen that oil and other substances will be deflectedand prevented from accumulating on the terminal. Suitable projections 19extend from the said terminal and are adapted to coact with an annularstationary terminal surface provided on theunder-side of the sleeve-20of the outer shell 1. As shown in the drawings'this terminal surface onthe sleeve 20 is annular, but I do not limit myself to such shape, asvarious other contours can be provided.

A tubular threaded washer 21 'is-interposed between the movable terminal14 and the lower end of the body portion 4 and serves to confine packing22 about the rod or stem 10 and prevent the entrance of oil, carbon orthe products of combustion within the body portion.

This washer 21 is constructed with a hea 23, between which and theupper'beveled surface of themovable terminal 14, a space 1s preferablyprovided. This space can be regulated as occasions require.

As hereinbefore mentioned, this terminal 14 is movable and free torotate about the vice it will be apparent that the successivesparkingbetween the movable and stationary terminals will produce avibrato action upon themovable terminal 14:, which is sufiicient todislodge the products .of' combustionoil and other substances as theyencircle the lower end of the spark plug immediately following theexplosion stroke of the piston. The force of the explosion and generalvibratory action of the motor will also tend to move this terminalmember 14 and assist in the reinoval of all carbon between the movableand stationary terminals, as well as in and around the washer 21 and theprotruding end of the body, portion 4.

' From the. foregoing it will be obvious that I have produced aneflicient and substantially self-cleaning spark plug capable of long andreliable service in motors of the in.- ternal combustion type.

Having ,thus described my invention what I claim and desire to secure byLetters Patent is:

1. A spark plug of the character described including in combination astationary terminal, an adjustable rod extending through said stationaryterminal, a movable terminal carried by said rod said movable terminalcomprising a disk having a coneshaped upper surface formed to $10 edownwardly toward the edge of said disk from I the center, and upwardlyextending sparking points arranged near the edge of the said cone-shapedupper surface and spaced from the stationary terminal.

2. A spark plug of the character described including in combination astationaryterminal, a rod extending through said stationary terminal, ahead formed on the lower end of said rod, an adjustable washer threadedon said rod. and'spaced from the aforesaid head, and a movable terminalloosely mounted between the said washer and head,

said movable terminal having a sloping upper surface and sparking pointsspaced from the stationary terminal.

In testimon whereof I aflix my signature in presence 0 two witnesses.

GEORGE L. FREEMAN.

Witnesses:

RICHARD -F. Hams, JAMES F. Frrz GIBBON.

